Student Doctor Mariam Keita Student Doctor Justin Lo Re OMS-III Rowan University School of Osteopathic Medicine

Learning Objectives 1. Know the main parts of the gastrointestinal (GI) tract 2. Know the functions of the “other” GI organs 3. Understand some GI diseases

 GI Tract (Tube) 1. Oropharynx: (mouth and throat) 2. Esophagus 3. Stomach 4. Small Intestine 5. Large Intestine (colon) 6. Anus  Other GI Organs 1. Liver 2. Pancreas 3. Gallbladder

GI

 Which of the following is not true about the gastrointestinal (GI) tract?  1) The stomach is the site where most of the absorption of nutrients occurs.  2) The liver synthesizes many things, including glucose.  3) The pancreas makes many digestive enzymes.  4) The oropharynx is the start of the GI tract.  5) The gallbladder is where bile is stored.

Oropharynx  Site where food enters the GI tract  Mastication: chewing  Salivary glands: saliva helps to start digestion

Esophagus  Tube that runs from mouth into the stomach  Very strong wall (why?)  “stratified”

Stomach  Continues digestion of food  Acidic environment: pH ~ 2  Due to lots of hydrochloric acid (HCl)  secretes pepsinogen  Pepsin: helps to break down proteins  secretes intrinsic factor  needed for Vitamin B12 absorption

 Why is the small intestine called “small”?  Why is the large intestine called “large”?

Small Intestine  3 parts: duodenum, jejunum, ileum  Secretes bicarb (a base)  why?  2 main functions:  Digestion of nutrients***  Absorption of nutrients***

Large Intestine and Anus  Large intestine = colon  Absorption of water  Feces collect at the end of the colon  Anus

Liver  Functions include:  Synthesis:  glucose  coagulation (clotting) factors  produces bile  lots of other stuff  Metabolism:  breaks down drugs, toxins, etc

Pancreas  Endocrine and Exocrine Pancreas (only focus on exocrine today)  Makes digestive enzymes  Enzymes then enter the small intestine to help break down our food into absorbable nutrients

Gallbladder  Gallbladder: site where bile is stored  Bile: helps to emulsify fat in our GI tract  Gallstone: precipitation (solid) of cholesterol and/or bile

Can you name some diseases that affect the gastrointestinal (GI) system? GI DISEASES

Gastroenteritis  Infection of the GI tract  Usually viral  Can have:  Nausea  Vomiting  Diarrhea  Fluids!

Colon cancer  Cancer of the colon (large intestine)  #2 cause of cancer death in USA  Colonoscopy  Helps to look through the colon to see if any polyps  Polyps can turn into colon cancer  Colonoscopy once every 10 years starting at 50 years old

Hepatitis  Hepatitis: inflammation of liver  jaundice  Can be due to  Alcohol  Viral infection (Hepatitis A, B, C, D, E)  Autoimmune

Questions  Which part of the GI tract secretes HCl (hydrochloric acid) to help with the digestion of food?  1) small intestine  2) stomach  3) colon (large intestine)  4) liver  5) esophagus

 A patient comes into your office with yellow skin and eyes. What GI organ do you immediately think has a problem?  1) oropharynx  2) small intestine  3) pancreas  4) liver  5) stomach

 At what site in the GI tract do most of the nutrients from our food get absorbed?  1) small intestine  2) stomach  3) oropharynx  4) esophagus  5) colon (large intestine)

 Where in the GI tract is bile made?  1) gallbladder  2) small intestine  3) pancreas  4) stomach  5) liver

 What’s the mainstay of treating any type of gastroenteritis?  1) antibiotics  2) aspirin  3) fluid replacement  4) vaccine  5) surgery